Can You connect c++ to your Java?

Answer 1

Yes ...
You can load Dll with java
Or use JNI with c++...
thera lots of ways but this is most common and simplest way...

Answer 2

To do this the modern way, you should check out polyglot programming with GraalVM.

https://www.graalvm.org/22.0/reference-manual/polyglot-programming/